1. Field of the Invention
The present invention relates to a power circuit supplying electric power to plural load circuits having different driving currents.
2. Discussion of the Background
When plural loads exist to be controlled by constant current such as LED (light-emitting diode), if driving currents of the plural loads are the same, a load circuit is formed by connecting the plural loads in series and connected to a power circuit, and the same current is passed to the plural loads.
If the driving currents of the plural loads are different, the plural loads are grouped for each driving current, plural load circuits are formed by connecting only loads having the same driving current in series, and the plural load circuits are respectively connected to different power circuits.
Some configurations of the power circuit are known such as a configuration in which each resistance connected with each load in series is connected to a common power circuit to limit driving current to be supplied to each load; and a configuration in which feedback of driving current is performed and constant current driving control is carried out using buck converters, etc.